Pluto is far more interesting than was previously believed, according to scientists. Since its discovery by humans in 1930, debate has raged about its status as a planet and its relationship with Charon, which many or may not be its moon. Now, new data has revealed Pluto to be potentially one of the most complex and diverse bodies in our solar system.
This week saw the publication of five research papers by scientists with access to data and photographs gathered by the New Horizons probe, which passed the dwarf planet last July. One paper discusses the environmental situation on Pluto, noting that not only is it far colder than had been predicted, but that its atmosphere is leaking into space far more slowly than anybody had previously realised. Whereas many had thought it similar to Triton, a moon of nearby Neptune, this and other data shows that Pluto is unlike almost anywhere visited by humanity and its representatives.
A separate paper has concluded that the planet’s surface ice is far from uniform. It consists of carbon monoxide, water, methane and nitrogen, but in varying combinations that have intrigued the scientists analysing the data. Whilst some parts of the planets are covered in nitrogen ice, others are dominated by methane ice and one area, Sputnik Planum, contains large areas that see various types of ice coexisting in one location.
“I don’t know any other place in the entirety of the outer solar system where you see anything like this,” according to New Horizons principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado. Speaking to Space.com, he said that the discovery of diverse conditions such as those on Pluto was “unprecedented”, adding that only Earth could boast of having such a range of environmental conditions.
Pluto’s five moons also received attention from New Horizons. Charon, which is half the size of its mother planet, is vastly different. It shows little evidence of the recent geological activity so clearly visible on Pluto, and its ice is uniform, consisting mainly of water and showing no signs of the glacial movement detectable on the body it orbits. The four smaller moons are tiny compared to Charon, and the available data showed that they are spinning at speed and their rotations are off-kilter. This supports previous conclusions that the four smaller bodies are shrapnel from the celestial collision that formed Pluto and Charon, two bodies that scientists increasingly see as a binary system.
As for New Horizons, it is still out there, going further and further into space. It is currently en route to a small Kuiper Belt object designated 2014 MU69, which sits approximately 1 billion miles (1.6 billion km) beyond Pluto. If the craft makes it and the project continues to receive funding, there could be revelations about yet another other body that shares our tiny corner of the universe. As one popular science fiction character would say, the results could be “fascinating”.